/*
* Bytecode Analysis Framework
* Copyright (C) 2003,2004 University of Maryland
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package edu.umd.cs.findbugs.ba.bcp;
import org.apache.bcel.generic.ConstantPoolGen;
import org.apache.bcel.generic.FieldInstruction;
import org.apache.bcel.generic.Instruction;
import org.apache.bcel.generic.InstructionHandle;
import org.apache.bcel.generic.PUTFIELD;
import org.apache.bcel.generic.PUTSTATIC;
import edu.umd.cs.findbugs.ba.DataflowAnalysisException;
import edu.umd.cs.findbugs.ba.vna.ValueNumber;
import edu.umd.cs.findbugs.ba.vna.ValueNumberFrame;
/**
* A PatternElement representing a store to a field. Variables represent the
* field and the value stored.
*
* @author David Hovemeyer
* @see PatternElement
*/
public class Store extends FieldAccess {
/**
* Constructor.
*
* @param fieldVarName
* the name of the field variable
* @param valueVarName
* the name of the variable representing the value stored
*/
public Store(String fieldVarName, String valueVarName) {
super(fieldVarName, valueVarName);
}
@Override
public MatchResult match(InstructionHandle handle, ConstantPoolGen cpg, ValueNumberFrame before, ValueNumberFrame after,
BindingSet bindingSet) throws DataflowAnalysisException {
Instruction ins = handle.getInstruction();
FieldInstruction fieldIns;
Variable field;
// The instruction must be PUTFIELD or PUTSTATIC
if (ins instanceof PUTFIELD) {
fieldIns = (PUTFIELD) ins;
int numSlots = before.getNumSlots();
ValueNumber ref = before.getValue(isLongOrDouble(fieldIns, cpg) ? numSlots - 3 : numSlots - 2);
field = new FieldVariable(ref, fieldIns.getClassName(cpg), fieldIns.getFieldName(cpg), fieldIns.getSignature(cpg));
} else if (ins instanceof PUTSTATIC) {
fieldIns = (PUTSTATIC) ins;
field = new FieldVariable(fieldIns.getClassName(cpg), fieldIns.getFieldName(cpg), fieldIns.getSignature(cpg));
} else {
return null;
}
Variable value = snarfFieldValue(fieldIns, cpg, before);
return checkConsistent(field, value, bindingSet);
}
}